1. Achillea millefolium Linnaeus, Sp. Pl. 2: 899. 1753.
Herbs, perennial, 40-100 cm tall, with long rhizomes; stems erect, unbranched or branched in upper part, often with short sterile branches at leaf axils above middle, striate, usually white villous. Leaves sessile; leaf blade lanceolate, oblong-lanceolate, or sublinear, 5-20 × 1-2.5 cm, (2 or)3-pinnatisect, abaxially densely villous, adaxially densely depressed glandular punctuate; ultimate segments lanceolate to linear, 0.5-1.5 × 0.3-0.5 mm, apex cartilaginous-mucronulate. Synflorescence a terminal flat-topped panicle 2-6 cm in diam. Capitula many. Involucres oblong or subovoid, ca. 4 × 3 mm; phyllaries in 3 rows, elliptic or oblong, 1.5-3 × 1-1.3 mm, scarious margin pale yellow or brown; midvein convex. Paleae oblong-elliptic, scarious, abaxially yellow gland-dotted. Ray florets 5; lamina white, pink, or violet-red, suborbicular, 1.5-3 × 2-2.5 mm, apex 2- or 3-denticulate. Disk florets yellow, tubular, 2.2-3 mm, exterior gland-dotted, apex 5-lobed. Achenes greenish, oblong, ca. 2 mm, with white lateral ribs. Corona absent. Fl. and fr. Jul-Sep. 2n = 18, 27, 36 + 0-2B, 45, 54 + 0-3B, 72.
Widely cultivated in China, locally naturalized. Nei Mongol, Xinjiang [native to temperate and alpine regions of N Hemisphere].
Achillea millefolium is a very variable species with many synonyms outside of China.
The whole plant is used medicinally for inducing sweat and dispelling diseases.